A nebulizer is used when a gas having a high oxygen concentration is supplied to a patient. The nebulizer is configured by a bottle in which water is contained, and a lid member that is detachably attached to the bottle. The nebulizer is designed so that, by supplying an oxygen gas from a supply unit of the oxygen gas attached to the lid member, water contained in the bottle is sucked, while air is also sucked so that the sucked water is humidified as fine aerosol; thus, gas humidified by the aerosol with a high oxygen concentration can be supplied to a patient.
In the nebulizer, by discharging an oxygen gas from an orifice that is formed on a nozzle member, water contained in the bottle is sucked from a suction pore disposed near the orifice, and by allowing the water to collide with a baffle that is disposed face to face with the orifice, fine aerosol can be formed.
When the aerosol has large particles, they are deposited on an upper respiratory tract of the patient to cause a problem that they are not allowed to reach air vesicles; therefore, it is considered that the size of the particles is preferably set to about 5 μm or less. For this reason, in general, the flow rate of the oxygen gas to be supplied is set in association with the diameter of the orifice. Therefore, a flowmeter is attached to an oxygen piping system to be connected to the nebulizer so that by adjusting the flowmeter, the oxygen flow rate to be supplied to a patient is adjusted. In the case of a nebulizer generally used at present, the flow rate of the oxygen gas is set to 15 liters per minute even in the maximum level.
Near the nozzle member of the nebulizer, a suction pore for air whose opening area is designed to be adjusted is formed, and air having a quantity that corresponds to the degree of opening is sucked from the suction pore according to the discharge of the oxygen gas from the orifice formed in the nozzle member so that a mixed gas of the oxygen gas and aerosol is formed. Therefore, by managing the degree of opening of the suction pore for air and the flow rate of the oxygen gas, an oxygen concentration of a gas to be supplied to a patient can be set, and the quantity of gas supply can also be set.